Fix height of InstallDirDlg description in Russian localization

Before:
![before](https://cloud.githubusercontent.com/assets/4525736/3143523/721a8cc8-e9fe-11e3-9fbd-811786645dea.PNG)

After:
![after](https://cloud.githubusercontent.com/assets/4525736/3143520/68ce938a-e9fe-11e3-956f-ed13134864f4.PNG)